Starters for small internal combustion engines



Sept. 25, 1962 s. z. SIWEK I 3,055,351

STARTERS FOR SMALL INTERNAL COMBUSTION ENGINES Filed 001.- 10, 1960 4ts-Sheet 1 28 N INVENTOR.

Sept. 25, 5. Z. SIWEK STARTERS FOR SMALL INTERNAL COMBUSTION ENGINESFiled 001;. 10, 1960 4 Sheets-Sheet 2 INV EN TOR.

51 4/7/6 Z. 5006/? BY Sept. 25, 1962 s. z. SIWEK 3,055,351

STARTERS FOR SMALL INTERNAL COMBUSTION ENGINES Filed Oct. 10, 1960 4Sheets-Sheet 3 INVENTOR. 5/4/7/4; Z. 50%, BY

I ,if/amgya Sept. 25, I962 s. z. SlWEK 3,055,351

STARTERS FOR SMALL INTERNAL CUMBUSTION ENGINES Filed Oct. 10, 1960 4SheetsSheet 4 INV EN TOR.

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United States Patent 3,055,351 STTERS FOR SMALL INTERNAL CGMBUSTIONENGINES Stanley Z. Siwelr, Chicago, 111., assignor to PioneerGen-E-Motor Corporation, Chicago, Ill. Filed Get. 10, 1960, Ser. No.61,545 6 Claims. (Cl. 123-479) The present invention is directed to newand useful improvements in starting mechanisms for engines and isparticularly applicable to small internal combustion engines of theclass commonly found on power lawn mowers.

It has heretofore been proposed to utilize a spring mechanism forstarting small internal combustion engines of this class. Priormechanisms of this type have utilized some form of crank for winding upa spring and then releasing the spring so that the energy of the springturns over the engine crank shaft for a few revolutions to enablestarting of the engine. The major purpose of the present invention is toimprove mechanisms of this class by so designing the mechanism thatimpact forces in the mechanism are held to a minimum with a resultantlonger life for the various parts of the mechanism; to so arrange amechanism of this class that it is easily actuated by remote control; toincrease the safety of operation of mechanisms of this class; and toprovide a mechanism of this class which is highly rugged in constructionand durable in use, and which is, at the same time, economical tomanufacture.

Other purposes will appear from time to time in the course of theensuing specification and claims, when taken with the accompanyingdrawings, in which:

FIGURE 1 is a side elevation of a typical gasoline engine provided witha starter mechanism of the present invention;

FIGURE 2 is a sectional illustration of the starter mechanismillustrated in FIGURE 1;

FIGURE 3 is a top view of the mechanism illustrated in FIGURE 2;

FIGURE 4 is a side view of a portion of the mechanism illustrated inFIGURE 3;

FIGURE 5 is a sectional view of the mechanism illustrated in FIGURE 4and taken along the section line 55 of FIGURE 3;

FIGURE 6 is a sectional view of a portion of the mechanism shown inFIGURES 2 and 3 and taken on the section lines 6-6 of FIGURE 2;

FIGURE 7 is a sectional view of another portion of the mechanism andlooking in the direction of the arrows of section lines 7-7 of FIGURE 2;

FIGURE 8 is a top view of a modified form of handle and clutch assembly;and

FIGURE 9 is a sectional view of the modified form of clutch illustratedtaken along lines 89 of FIGURE 8.

Like elements are designated by like characters throughout thespecification and drawings.

With specific reference now to the drawings and in the first instance toFIGURE 1, the numeral 10 generally designates an internal combustionengine of the class to which the present invention is applicable, and asshown in FIGURE 1 is utilized to rotate a cutter blade 11 which ispositioned beneath the base 12 of a power lawn mower. Cutter blade 11,as is typical in machines of this class, is coupled to the crank shaft13 of the engine so as to rotate the cutter blade, through rotation ofthe crank shaft.

In accordance with the present invention, a starter mechanism generallydesignated at 14 is mounted on the top of the engine 111 shown inFIGURE 1. As illustrated in the drawing, the starter mechanism 14includes a handle 15 which is adapted, through mechanism presently to bedescribed, to wind and tension a sprin so that the 3,055,351 PatentedSept. 25, 1962 energy of the spring can subsequently be released tocause rotation of crank shaft 13 and start engine 10.

As is seen best in FIGURES 2 and 3, the starter mechanism includes ahousing assembly '16 which is of an inverted cup shape and which isfixed to a shroud 17 for the engine as by means of bolts 18, which boltsare passed through an outwardly extending flange 19 at the base of thehousing '16. Housing 16 supports a stub shaft 20 therein as by means ofa bearing block 21 fixed to the upper portion of the housing. Handle 15is fixed to the upper portion of the stub shaft 20 so as to bepositioned exteriorally of the housing 16' and to overlie the same as isseen best in FIGURE 2. The handle 15 is sectionally formed, with onesection 22 fixed to the stub shaft 20 and the other section 23 hinged tosection 22 as by means of a pivot pin 24 The outer end of handle 15, orthat end most remote from the stub shaft 20 carries an actuating knob orhandle 25 which the operator may easily grasp for rotation of the stubshaft 20. Handle 15 is so mounted that rotation of handle 15 and stubshaft 20 is only permitted in one direction. A coil spring 26 surroundsthe cylindrical surface of the bearing block 20 in close fittingrelation and has its upper end fixed to handle portion 22 as at 27. Theother end of the spring is free to slide on bearing 21. Thus, whenhandle 15 is rotated in one direction as when the operator intends tocrank the mechanism for starting (or clockwise in FIG- URE 2), thespring tends to be unwound, thereby causing a slight radial expansion ofthe spring and allowing free rotation of the handle with respect to thebearing post 21. On the other hand, when the handle and stub shaft arerotated in the opposite direction, the spring is pulled tightly againstthe bearing post 21 and frictionally binds against the bearing post,thus preventing this direc tion of relative rotation.

The other end of stub shaft 20 carries a spring support 28 which isrotatable thereon. Support 28 is in the form of an upright cup or drumto which a ratchet wheel 29 is fixed at the lower end thereof. Thespring support 28 has a coiled spring 30 positioned therein with one endfixed to the wall of the cup as at 31 in FIGURE 6. The other end of thespring (the inner end thereof) includes an enlarged knob-like portion 32, which is adapted for engagement with a recess 33 on a spirally shapeddriving member 34, which is fixed to the stub shaft 20 as by means ofthe pin 26a. Rotation of the driving member 34 in one direction, as forexample the clockwise direction in FIGURE 6, will bring the recess 33against the knob-like portion 32 of the spring and further rotation ofthe driving member 34 will then wind the spring. The particular spiralshape of the driving member 34 enables the spring 32 to move clockwisewith respect to the driving member without abutting against the same.

A pawl support 35 is positioned beneath the spring support 28 and has agenerally cup-shaped form. A plurality of pawls 36 are pivoted on thepawl support as by means of pivot pins 37 and are equally spaced aboutthe axis of the stub shaft 20 and ratchet wheel 29. Each of the pawlshas a flat end surface 38 which is adapted for abutting contact withsimilarly formed edges 39 of the ratchet wheel 29. Springs 41 bias eachpawl inwardly towards the position illustrated in FIGURE 7 wherein theedges of the pawls are in abutting and driving engagement with the edges39 of the ratchet wheel 28. The springs 40 have sufficient strength tobias the pawls inwardly when the mechanism is idle and during slowrotation of the crank shaft 13 of the engine. On the other hand, thesprings are sufficiently weak that they allow the heavier ends of thepawls (or those with sur faces '38) to move outwardly toward the outercircumferential wall 41 of the cup after ignition of the engine, thecentrifugal force then developed being suificient to J swing the pawlsoutwardly and out of engagement with the edges 39 of the ratchet wheel29.

The lower central portion of the pawl support is bolted to the end ofthe engine crank shaft 13 as by means of the bolt 42. The lower portionof the pawl support includes depending finger portions 43 that arestamped from the central portion of the support and are bent downwardlyso as to fit into recesses in hub portion 44 of a flywheel 45 that isfixed to the crank shaft 13. The finger portions 43 thus securely keythe pawl support to the flywheel and to the crank shaft.

The housing 16 supports a locking mechanism generally designated at 46in FIGURE 3, which mechanism is adapted to selectively hold the springsupport 28 in fixed position relative to the housing 16 and to allowrelease thereof at the desire of the operator, as is seen best inFIGURES 3, 4, and 5. This locking mechanism includes a lever 47 which ispivoted to the flange of the housing 16 as by means of the rivet 48which is fixed to flange 19 with a reinforcing plate 49. Reinforcingplate 49 has side portions fixed to the flange 19 and includes an offsetend 50 that extends through a slot 50a in the lever 47. Lever 47, as isseen best in FIG- URE 3, includes an end portion which, during pivotalmovement of the lever 47 in the direction of the arrows illustrated inFIGURE 3, moves toward and away from the upstanding wall of the springsupport 28. A spring 51 is fixed to the outer end of the lever 47 and tothe inner end of the reinforcing plate 49. The spring 51 is adapted tohold the lever 47 in one of two opposite positions, either a lockedposition where its end 47a is positioned counterclockwise from theposition illustrated in FIGURE 3 and in contact with the wall of support28 or a release position wherein the end 47a is positioned clockwisefrom the position illustrated in FIGURE 3, and where the cutaway portion47b is opposed to support 28 and spaced therefrom.

As will be noted in FIGURES 3 and 6, the spring support 28 includes aplurality of corner portions 52 which project outwardly from the mainbody portion of the spring support and which are adapted for abuttingcontact with the inner end of the lever 47 when the lever 47 is in thelocked position. In this locked position, the inner end of the leverwill not contact the remaining portions of the spring support, whereasit contacts the projecting portions 52 of the spring support when one oranother of these portions is opposed thereto.

A control cable, as is diagrammatically represented at 53 in FIGURE 3,may lead to a remote position so that the operator may move the lever 47to the release position to allow rotation of the drum 28.

FIGURES 8 and 9 designate another form of clutch between the windinghandle and the spring winding shaft of the assembly. In FIGURES 8 and 9the housing is designated at 60 and carries an actuating shaft 61 whichis adapted to wind a coil spring for the subsequent release of energy inthe same fashion that the shaft Winds the coil spring in FIGURES 1through 7, inclusive. The parts of the starter mechanism which are notshown in FIGURES 8 and 9 may be assumed to be identical to those inFIGURES 1 through 7, inclusive.

A foldable handle 62 of the precise type as illustrated in FIGURES 1through 7, inclusive, is fixed to the shaft 61 and has an outer section62a pivoted as at 63 to an inner section 62b. The shaft 61 is journalledfor rotation in a bearing 64 which is fixed to the upper wall of thehousing 60. In FIGURES 8 and 9, the outer surface of the bearing 64 isformed with a plurality of ratchet teeth 65.

A pawl 66 is pivoted to the under surface of the handle section 6211 asat 67 and is adapted for engagement with the teeth 65 of the ratchet. Aspring 68 is connected between the pawl 66 and a portion of the handlesection 62b, so as to bias pawl 66 into engagement with the ratchetteeth 65.

The ratchet teeth are so formed that they allow rotation of the handle62 in one direction, as the clockwise direction in FIGURE 8, whilepreventing rotation of the handle in the opposite direction.

During the winding operation, the spring 68 biases the pawl 66 intoengagement with the teeth 65, although during clockwise rotation ofhandle 62, the pawl simply slides over the teeth. A portion 71 of thepawl protrudes through an opening '72 in handle section 62 when pawl 66is forced outward by engagement with the high point of the teeth.

After the spring of the starter assembly is wound and ready for thedelivery of energy, the outer handle section 62a is folded over theinner handle section 62b, and in so doing the flange of the outer handlesection closes opening 72 and prevents outward movement of pawl 66.Thus, folding of the handle brings about a positive lock between thehandle and ratchet teeth 65 and prevents any counterclockwise rotationof the handle.

In operation, the operator unfolds the handle 15 to the extendedposition and moves the tripping mechanism 46 to the locked position. Hethen cranks handle 15 and during initial rotation of the handle 15, thespring driver 3-4 will move into engagement with the inner end 32 of thespring and will tend to wind the spring 30. This initial rotation willrotate the spring support 28 into a position wherein one of theprojecting corners 52 abuts against the inner end 47a of the lever 47.Continued rotation of the handle by the operator winds the spring.During this same initial rotation of the handle, the ratchet wheel 29which is carried by the spring support 23 also moves through a partialrevolution and this partial revolution is sufiicient to cause the pawlsto snap into abutting engagement with the teeth of the ratchet wheel 29,as in FIGURE 7. With the pawls thus positioned, the ratchet mechanism islocked in place and ready to deliver rotational energy to the crankshaft 13 without lost motion.

After a few turns of the handle, which is sufiicient to store enoughenergy in the spring for the starting of the engine, the operator thenholds the handle across the stub shaft 20 and into the dotted lineposition illustrated in FIGURE 2.

Then by moving the lever 47 to the release position, the spring 30 thenrotates the spring support 28 and the ratchet wheel 29 carrying withthem the pawls and pawl support, flywheel, and crank shaft in aclockwise direction, thus cranking the engine for the startingoperation. After the engine starts, the pawls move out of engagementwith the ratchet wheel 29, and in the meantime, the spring drum 28 willhave coasted to a stop.

It should be noted that if the engine tends to buck or rotate in thedirection counter to that direction induced by the spring, the pawlssimply move idly over the ratchet teeth, thus preventing any rotation ofhandle 15.

It should also be noted that the connection between the handle and thestub shaft 15 is such that the handle can only be wound in the directionof winding the spring. Spring forces can never be transmitted to causecounter rotation of the handle by reason of the fact that the spring 26of the handle binds against the bearing post and precludes suchrotation. Furthermore, by the use of spring 26, the operator positivelyknows the proper direction for winding the handle for the startingoperation.

The form of the handle clutch in FIGURES 1 through 7 is extremely quietin operation. Furthermore, the particular spring clutch described andillustrated provides a substantially instantaneous grip of the bearingsurrounding the shaft 20 and insures a positive locking of the handle tothe housing.

The particular arrangement of the spring driver and inner end of thespring is advantageous from the standpoint of avoiding impact forces andwear on the spring and driver. In this connection, it should be notedthat after the spring has been released to turn over the engine, theinertia of the spring will tend to move the inner end thereof 32 awayfrom the recess 33 and tend to move in a clockwise direction, as inFIGURE 7. The particular shape of the spring driver 34 allows the knobto simply ride thereover freely until the inner end of the spring hascome to rest. This is also true in the event that the engine bucks, andcauses counterclockwise movement of the spring support 28. In this eventthe inner end 32 of the spring may simply move around the spring driverwithout meeting any deleterious impact forces.

Furthermore, when the spring drum 28 and spring 30 are coasting to astop, by virtue of the expenditure of the springs energy, at which timethe end 32 of the spring comes away from recess 33 and moves clockwisearound the driver 34, the rising camming surface of the driver then putsa gradually increasing radial pressure on end 32, thus helping thespring and spring support to come to a gradually decelerated and smoothstop.

The positive engagement of the pawl and ratchet, locking of drum 28, andengagement of spring 30 and driver 34, all of which is brought aboutduring initial rotation of handle 15, insures a positive drivingconnection among the elements without lost motion and deleterious impactforces.

The particular release mechanism is advantageous both from thestandpoint of allowing remote control and selective operator control ofthe starting of the engine and at the same time insuring positivelocking of the spring drum 28.

Whereas I have shown and described an operative form of the invention,it should be understood that this showing and description thereof shouldbe taken in an illustrative or diagrammatic sense only. There are manymodifications in and to the invention which will fall within the scopeand spirit thereof and which will be apparent to those skilled in theart. The scope of the invention should be limited only by the scope ofthe hereinafter appended claims.

I claim:

1. In a starter mechanism for internal combustion engines, a housingadapted to be mounted on said engine and a drum mounted for rotation insaid housing, said drum having a ratchet thereon for cooperableengagement with pawls carried with the shaft of said engine duringrotation thereof, a coil spring positioned within said housing and drumand means for winding said spring so that said spring tends to rotatesaid drum in a predetermined direction, said drum having angularlyspaced projections on the peripheral wall thereof, a locking levercarried by said housing and engageable with one of said projections inaccordance with the angular disposition of said drum, said projectionsbeing spaced so as to allow a predetermined rotation of said drum priorto engagement with said lever, said lever being movably mounted on saidhousing so as to be selectively moved into engagement with one of saidprojections and out of engagement therewith such that when moved out ofengagement with said one projection, said drum is free to rotate underthe action of said spring and cause a consequent rotation of said engineshaft.

2. The structure of claim 1 wherein the outer end of said coil spring isfixed to said drum and the inner end of said spring is abutable againstan abutment carried by a winding shaft mounted for rotation in saidhousing.

3. The structure of claim 2 wherein said winding shaft has a springdriver carrying said abutment, said driver having a camming surface ofprogressively increasing radial dimension, the camming surface havingthe greatest radial extension adjacent the abutment surface thereof.

4. The structure of claim 1 wherein said lever is pivoted to saidhousing and including an actuating cable coupled thereto.

5. A starter mechanism for internal combustion engines including anengine having a drive shaft, a housing mounted on said engine and a drummounted for rotation in said housing, pawl and ratchet means carried bysaid drum and said shaft and being engageable with one another uponrotation of said drum in a predetermined direction to cause rotation ofsaid shaft, a coil spring positioned within said housing and drum andmeans for winding said spring so that said spring tends to rotate saiddrum in a predetermined direction, said drum having angularly spacedprojections on the peripheral wall thereof, a locking lever carried bysaid housing and engageable with one of said projections in accordancewith the angular disposition of said drum, said projections being spacedso as to allow a predetermined rotation of said drum prior to engagementwith said lever, said lever being movably mounted on said housing so asto be selectively moved into engagement with one of said projections andout of engagement therewith such that when moved out of engagement withsaid one projections, said drum is free to rotate under the action ofsaid spring and cause a consequent rotation of said engine shaft.

6. The structure of claim 5 wherein said drum is cup shaped and theupstanding peripheral wall thereof is deformed so as to provide saidangularly spaced projections.

References Cited in the file of this patent UNITED STATES PATENTS2,563,719 Goldberg et a1. Aug. 7, 1951 2,744,586 Blankenburg May 8, 19562,804,173 De Millar Aug. 27, 1957 2,869,682 De Millar Jan. 20, 19592,950,780 De Millar Aug. 30, 1960 2,955,584 Vakos et a1 Oct. 11, 19602,974,658 Russell Mar. 14, 1961 2,997,997 Glenn Aug. 29, 1961 2,999,489Coughlin Sept. 12, 1961 2,999,490 Hamman Sept. 12, 1961

